(a) Field of the Invention
The present invention relates to a CPU and circuit board mounting arrangement and, more particularly to such a CPU And circuit board mounting arrangement, which enables a CPU without contact pins to be vertically loaded in a CPU connector and electrically connected to a circuit at the bottom side of the CPU connector.
(b) Description of the Prior Art
Regular CPUs, subject to their mounting design, include two types, i.e., the CPU 10 with pins 101 (see FIG. 1), and the CPU 20 with solder balls 201 (see FIG. 2). The procedure of installing pins 101 in the bottom pads of the CPU 10 is complicated and critical. In order to achieve satisfactory electric conductivity, the pins 101 are plated with a layer of gold. The gold coating greatly increases the cost of the pins 101. Further, the pins 101 may be biased or broken during installation. The CPU 20 shown in FIG. 2 is provided with solder balls 201 at the bottom side for reflow-soldering to a circuit board 30 directly (see FIG. 3). The CPU mounting design still has drawbacks. The use of the expensive cost of the solder balls 201 greatly increases the installation cost. The installation of the solder balls 201 is also complicated. Furthermore, the CPU 20 cannot be removed from the circuit board 30 for repair or replacement when soldered.
FIG. 4 shows the installation of the CPU 10 with pins 101 in a CPU connector 40 at a circuit board 30. During installation, the pins 101 of the CPU 10 are respectively inserted into the respective terminal slots 401 of the CPU connector 40, and then the locking lever 402 of the CPU connector 40 is turned in direction xe2x80x9caxe2x80x9d to shift the top cover plate 403 of the CPU connector 40 forwards from the unlocking position to the locking position, thereby causing the pins 101 to be moved from the non-contact position shown in FIG. 5 to the contact position shown in FIG. 6 where a pin 101 is forced into contact with a respective contact plate 404, which is provided with a solder ball 405 at the bottom side that is reflow-soldered to the circuit board 30. This CPU and circuit board mounting arrangement enables the user to detach the CPU 10 from the circuit board 30 for repair or replacement. However, the gold coating of the pins 101 greatly increases the cost of the CPU 10. Further, the pins 101 may be biased or broken during installation.
As indicated above, the aforesaid CPU connector 40 comprises a horizontally slidably top cover plate 403, and a locking lever 402 adapted for moving the top cover plate 403 between the locking position and the unlocking position. This design of CPU connector 40 does not fit the CPU 20 with solder balls 201.
The present invention has been accomplished to provide a CPU and circuit board mounting arrangement, which eliminates the aforesaid drawbacks. According to one aspect of the present invention, the CPU and circuit board mounting arrangement comprises a circuit board, a CPU connector soldered to the circuit board, and a CPU installed in the CPU connector and electrically connected to respective contacts of the circuit board. The CPU connector comprises a plurality of terminals soldered to respective contacts of the circuit board and so installed that the CPU is vertically loaded in the CPU connector, keeping respective bottom pads of the CPU in contact with the terminals of the CPU connector respectively, achieving electric connection between the CPU and the circuit board. According to another aspect of the present invention, the CPU connector comprises a plurality of terminal slots, which hold the terminals respectively in a sloping position for contacting the bottom pads of the CPU. According to still another aspect of the present invention, the terminals of the CPU connector each have a top contact end sloping in one direction for contacting the bottom pads of the CPU positively. According to still another aspect of the present invention, a heat sink is fastened to the circuit board and pressed on the CPU, keeping the CPU in contact with the terminals of the CPU connector. According to still another aspect of the present invention, a pressure member may be directly pivoted to the CPU connector and locked by lock means to hold down the CPU in the CPU connector, keeping the bottom pads of the CPU in contact with the terminals of the CPU connector positively.